1. Field of the Invention
The present invention generally relates to a cleaning method of a substrate processing container of a substrate processor, and especially relates to a cleaning method of a membrane formation apparatus by remote plasma generation.
2. Description of the Related Art
In a substrate processor that forms a membrane on a target substrate, for example, a CVD (chemical vapor deposition) apparatus, the target substrate is laid in a substrate processing container, and predetermined membrane formation is performed. There being a huge number of examples of thin films formed on substrates, deposits are also made (thin films are also formed) on the inner wall and members, such as a substrate holding stand, of the substrate processing container. Such undesired deposits become thicker as membrane formation is repeated, and the undesired thin films will be exfoliated. Such exfoliated sediment floats in the substrate processing container, and is taken into the thin film to be formed on the substrate during the membrane formation process. This degrades the quality of the thin film, and is a problem.
In order to cope with the problem, a cleaning method of removing sediment as described above from a substrate processing container is proposed (for example, JPA 10-149989). According to the cleaning method, a remote plasma generating unit for generating fluorine radicals for cleaning is prepared outside of the substrate processing container, wherein NF3 is excited by 2.45 GHz microwave power so that the fluorine radicals are generated. Then, the fluorine radicals are introduced into the substrate processing container such that the sediment is made to evaporate and be discharged out of the substrate processing container.